Harry c



(No Model. H. C. CLAY.

BALANCED SLIDE VALVE.

N0. 536,562. PatentedMar. 26, 1895.

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NITED TATE-S PATENT OFFICE.

HARRY O. CLAY, OF DAYTON, OHIO, ASSIGNOR TO THE BROWNELL & COM- PANY, OF SAME PLACE.

BALANQED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 536,562, dated March 26, 1895. I

Application filed DecemberZl, 1894. Serial No. 532,549- (No model.)

To all whom it may concern.-

Be it known that I, HARRY O. CLAY, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Balanced Slide-Valves; and

I do hereby declare that the following is a full,

clear, and exact description of the invention,

which will enable others skilled-in the art to to which it appertains to make and use the same,

reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in balanced slide valves for steam engines, the featuresof which will be fullyhereinafter described and claimed.

The object of myinvention is the construction of a valve adapted to a cylinder having double ports at both ends, which shall receive the steam from beneath near the center of the valve and exhaust the same at the end of said valve into the steam chamber, andthe two parts of said valve being so adjusted to its seat and the cap-plate of the steam chamber, that the pressure on said seat will be slight and so nearly balanced, that but little friction results from the necessary reciprocating 3o movement of said valve.

The invention only involves the compound valve in its relation to a cylinder with bifurcated ports, the seat and cap of the steam chamber; and only so much is shown in the 3 5 illustration as will make clear the function of said valve, as in other respects the parts of the engine are identical with a well known class of engines. The construction is illustrated in the accompanying drawings, in

Figure 1 is a central, transverse, vertical section of the cylinder and valve. Fig. 2 is a central, longitudinal, horizontal section of the same. Fig. 3 is a plan of the valve looking 5 at its face.

Like letters and numerals designate like parts throughout the several views.

The engine cylinder A is adapted to have its left end bolted on against the bed, and is cast with the steam chamber E as an integral part, and is on the side of said cylinder. A

is a metallic lining to retain material that is a poor conductor of heat. The ports '7, communicating with the bore at the ends, terminatein a plane surface within the steam chamber forming the valve seat. These usual end ports have the bifurcated branches 8, that terminate near the center of the steam chamber. The end ports 7 have double the capacity of the inner ports 8, and the exhaust is quite 6o exclusively through the former ports. At the top of the steam chamber is the inlet orifice 9, to which is attached the pipe communicating with the steam boiler. In the bottom is the outlet orifice 10 to which is attached the exhaust pipe. The position of this orifice is indicated in Fig. 2 by the circular dotted line at 10. The valve comprises two parts, viz, part B being flat on its bearing surface, which is vertical in position, and the cylindrical part 0, which is nicely fitted to move within the circular orifice of the other part. The top ofthe latter part is nicely fitted to close steam tight against the closingplate D of the steam chamher. This part has the transverse arms 1 to brace the sides, and from their intersection the hub 2 projects inwardly, and which serves to hold the spiral spring 3 in position. As the bearings are steam tight, the only portion engaged by the steam to produce movement, is the area of its inner circular surface, which gives pressure against the closing plate, and serves to keep the steam within the interior of the valve. The only use of the spiral 8 spring is to keep the cylindrical part of the valve against the plate or cap when the steam is not on.

The valve B isquadrangular on its bearing surface, and the outer part Bis circular. It has the long inlet orifice 15 at its longitudinal center, the port openings 6 6 near the ends, and the transverse shallow cavities 14 14. These cavities open to the interior of the steam chamber and are only partially exposed 5 to the inner port at the time of exhaust and are not designed for such use. The back is provided with the longitudinal ribs 16 and the cross-ribs 4. To the latter is attached the arm 5, which supports the inner end of the spiral spring. The projection 11 of the valve is slotted and holds the nut 12, by which the eccentric rod 13 is attached. Lugs 17 are on the under surface of the valve, and which bear against the lugs 18 of the steam chamber; and by this means the valve is held in horizontal position.

. In Fig. 2, the valve is shown in the position in which the steam enters the back end of the cylinder. It is seen that through the openings 15 and 6, the steam would enter to drive the piston forward as these open into the ports 8 and 7. At the other end the port 7is open at the end of the valve and the port 8 is open into the channel 14, through both of which the steam is exhausted into the steam chamber, to pass off through the exhaust pipe into the open air. The transverse channels are onlysubjected to the pressure within the exhaust chamber. IVhen the fittings are proper, the only pressure of the steam against the face of the valve is that portion which covers the ports, and as the steam acts from the interior of the valve, there is a sufficient increase of area of the interior over the exterior to hold the valve to its seat; and so near is this balance of pressure, that the friction as compared with the old form of slide valve is only slight. The excess of surface exposed to the action of the steam from within is much relieved by the counteractingpressure within the transverse channels, and which narrow proportionately the bearing surface of the valve.

Having fuliy described my invention, what I claim, and desire to secure by Letters Patent, is-

In a steam engine the combination of the cylinder provided with two series of ports terminating in end ports and the central livesteam port, the compound balanced slide valve provided with central opening coincident with said live-steatn port and the ports near the ends, which are adapted to alternately open to said outer and inner ports, said outer ports serving for the exhaust at the ends of said valve, substantially as shown and described.

In testimony that I claim the foregoing as my own I afiix my signature in presence of two witnesses.

HARRY C. CLAY.

WVitnesses:

B. PICKERING, GEo. W. OZIOR. 

